How do i convert string array into long array in java?

How do i convert string array into long array in java?

what i am having is:

i want to convert this into Long Arrays

please help in this regards.

Thanks in advance,
Birla

So the String array users now contains strings that contain all digits? You'll need to create a Long array of the same length as the String array and then iterate through the String array to fill the elements of the Long array:

Without iterating the array,Is there is any other way to do it.

Simply put, no. Whatever solution you use, in the end you will still need to change each separate string element into a long.

Jesper, I'd suggest one slight modification: use long instead of Long:

Birla Murugesan wrote:
Without iterating the array,Is there is any other way to do it.

Rob Prime wrote:Simply put, no. Whatever solution you use, in the end you will still need to change each separate string element into a long.

A more complicated answer ... Maybe. You already iterated once through the string, in order to split it into an array. Technically, there is a way to do without iterating through the array -- you can skip generating the array in the first place.

Instead of using split(), you can use find(), to get each "long" string element, in order to convert to a long -- in one pass.

Now, of course, whether this saves any time, is unclear.

Henry

Henry Wong wrote:

Birla Murugesan wrote:
Without iterating the array,Is there is any other way to do it.

Rob Prime wrote:Simply put, no. Whatever solution you use, in the end you will still need to change each separate string element into a long.

A more complicated answer ... Maybe. You already iterated once through the string, in order to split it into an array. Technically, there is a way to do without iterating through the array -- you can skip generating the array in the first place.

Instead of using split(), you can use find(), to get each "long" string element, in order to convert to a long -- in one pass.

Now, of course, whether this saves any time, is unclear.

Henry

I agree that splitting and parsing in one go would remove the need for a second iteration. And I doubt that using a Pattern / Matcher combination would be slower - because that's just what String.split uses - it delegates to Pattern.split which uses a Matcher. This splitting a string into longs would be something like this (code based on Pattern.split):
Of course that would require another iteration to turn the List<Long> into a Long[] or long[], but the List<Long> should be fine for most cases.

But the initial question was: "How do i convert string array into long array in java?" and that's impossible without a second iteration (I count recursion as iterating in this case).

Rob Prime wrote:Jesper, I'd suggest one slight modification: use long instead of Long:

Ok, but the OP specifically asked for a Long array. This line of your modified version does not work:

It should be:

Jesper Young wrote:

Rob Prime wrote:Jesper, I'd suggest one slight modification: use long instead of Long:

Ok, but the OP specifically asked for a Long array.

Actually, the OP asked for both:

How do i convert string array into long array in java?

i want to convert this into Long Arrays

This line of your modified version does not work:
data[i] = long.parseLong(users[i]);
It should be:
data[i] = Long.parseLong(users[i]);

Guess my mental search-and-replace worked too good